The answer is "global torrent".
Sociologist Todd
Alan Gitlin is an American, also a political essayist, writer, and social
observer. He is printed on the broad communications, governmental issues,
scholarly life and expressions of the human experience, for both popular and scholarly publications. Gitlin turned into a political activist
in 1960, when he joined a Harvard group called Tocsin, against atomic weapons.
Answer:
U-boats were used primarily to -gather information about enemy movements by tracking warships. -protect the German coast from attack by Allied ships and submarines.